insolubilization

It should neither be kept in the air contaminated with gaseous reductive matters, such as the products of the combustion of coal gas and petroleum, sulphydric or sulphurous emanations from any source, the fumes of turpentine oil, etc., which, by reducing the chromic salt, cause the insolubilization of gelatine, prevent the print to adhere on the support or the clearing of the image, which may even refuse to develop.

Photographic Reproduction Processes Peter C. Duchochois

They may even refuse to develop at all from the insolubilization of the gelatine.

Photographic Reproduction Processes Peter C. Duchochois

The addition of alcohol to the bichromate bath — sometimes recommended to harden the film and allow it to stand a higher temperature, and to hasten the desiccation of the tissue — is objectionable, for the spirits tend to reduce the bichromate, which is transformed into the green salt, and, therefore, a partial or complete insolubilization of the gelatine is the result.

Photographic Reproduction Processes Peter C. Duchochois

In neurodegenerative diseases specific proteins escape the cell's quality-control system and associate together, forming insoluble aggregates. ... we discovered that the aging process itself, in the absence of disease, leads to the insolubilization and increased aggregation propensity of several hundred proteins in the roundworm

ScienceBlogs Channel : Life Science 2010

As to the theory of this and similar processes, the insolubilization of the bichromate organic substance acted on by light was formerly attributed to the oxidation of the substance by the oxygen evolved during the reduction of the chromic salt into chromic oxide; but from the fact that oxidation generally tends to destroy organic matters, or to increase their solubility, it is more probable that it results from the formation of a peculiar compound of the substance with chromic oxide (J.W. Swan); moreover, gelatine imbued with an alkaline bichromate, then immersed first in a solution of ferrous sulphate and afterwards in hot water, is insolubilized with formation of chromium trioxide, Cr2O7K2+SO4Fe =

Photographic Reproduction Processes Peter C. Duchochois